Why didn't I think of that?

Here's a really simple, crazy invention some guy will probably make money with that anyone could have thought of on their own: the cordless jump rope.

It's perfect for the clumsy, [inventor Lester] Clancy said. "If you are still jumping, you're still using your legs as well as your arms, and getting the cardiovascular workout. You just don't have to worry about tripping on the rope."

It is also good for mental institutions and prisons where rope is a suicide risk, said Clancy, who works as a laundry coordinator in a state prison. And low ceiling fans aren't a hazard any more, he said.

There are moving weights in the handles that simulate the feel of the rope moving around.